The Crime Branch has started investigation into the quarry blast at Vazhakode, near Wadakkanchery in Thrissur district of Kerala, in which one person was killed and five injured.
Remains of high-capacity explosives were found during search by Forensic Department officials at the blast site.
Earlier, it was suspected that detonators used for fishing in the pond in the abandoned quarry had caused the blast. Fish farming is done in the pond.
Since the quarry owners have units at Chelakkara in Thrissur district, officials are investigating whether the explosives had been kept for use in those quarries.
The Crime Branch team led by Assistant Commissioner of Police P. Sasikumar visited the blast site. It is investigating how high-capacity explosives reached the quarry, which had been abandoned.
It is learnt that the licence of the quarry had expired in 2018. The probe team will check whether illegal quarrying was done there.
Meanwhile, the special team took statements of two of the injured as well as those living near the quarry.
The District Collector has submitted a preliminary report of the tahsildar and the forensic wing to the government.